Exam Flashcards
cause of listonellosis
Listonella anguilarium
who gets listonella
Marine fish - European sea bass, trout, eel, gilt head sea bream
predisposition for listonellosis
sudden increase in temperature
stress
poor water quality
high stocking density
entry of listonella
through intestine or damaged skin and then septicaemia
peracute listonella
asymptomatic death
cardiomyopathy
acute-subacute listonella
haemorrhage on head, abdomen, fins and operculum
pale liver
enlarged spleen
chronic listonella
ulcers
corneal opacity
blindness
diagnosis of listonella
isolate from spleen or kidney
treatment of listonella
oxytetracycline, florfenicol
based on susceptibility testing
prevention of listonella
vaccine
probiotics
decrease stocking density
cold water vibriosis
Alivibrio salmonicida
in Atlantic salmon and rainbow trout
listonella ordalli
in pacific salmon and rainbow trout
cause of aeromonas
aeromonas hydrophilia
cause of Pseduomonas
pseudomonas anguillispetica
who gets aeromonas and pseudomonas
aeromonas in freshwater fish
pseduoaeromonas in freshwater and marine fish
predisposing for aero/pseduomonas
they are secondary infections so other diseases
signs of aero/pseudomonas
hemorrhagic septicaemia
diagnosis pf aero/pseudomonas
isolate from kidney or spleen
treatment of aero/pseudomonas
antimicrobials in feed or inject the broodstock
columnaris also known as
saddleback disease
cause of columnaris
Flavobacterium columnare
who gets columnaris
all freshwater fish species
predisposing for columnaris
high temperature
poor water quality
stress
signs of columnaris
skin - increased mucus on head and body, grey circles with red edges
gills - white spots on filament tips
fins -lesions look like a saddle
diagnosis of columnaris
lesions - yellow white exudate
swab from lesions - columns of bacteria
treatment of columnaris
oxytetracycline, florfenicol, flumequine
prevention of columnaris
good husbandry
when do carp naturally spawn
1x/year in May/June 17-20degrees
carp sexual maturity
males - 2-5y
females 4-6y
what to do with carp broodstock
salt bath and anaesthetise with MS222 of benzocaine
weigh, tag and give GnRH and stitch genital papillae
harvest eggs and milt using dry method
add fertilisation solution (urea and NaCl)
add tannins and proteolytic enzymes to remove stickiness
what to do with carp eggs
incubate eggs in zuger jars for 3d at 23d
transfer to containers for 3-4d at 23degrees and down feed them
when larvae - feed them hard boiled egg yolk or Nauplii of Artemia spp
transport in PVC bags pressurised with O2 to a 0.5-2ha pond
stocking density = 300,000-400,000 larvae/ha
have to allow for temp acclimatisation
how to prep pond for carp
plough, lime and fertilise with poultry manure, plankton sieve and insecticide treatment
feeding of young carp
larvae - feed hard dough 2x/d
advanced fry (4-6w), restock and feed 2mm pellets 1x/d
1 summer fry - in same ponds or overwintering ponds
cold water bacterial diseases
Furunculosis
Enteric redmouth
bacterial cold water disease
columnaris
warm water bacterial diseases
carp erythrodermatitis
columnaris
marine bacterial diseases
vibriosis
pasteurellosis
tenacibaculosis
viruses in carp
spring viremia
carp pox
koi herpesvirus
koi sleepy disease
viruses in salmonids
VHS
IHN
infectious pancreatic necrosis
marine viruses
viral encephalopathy and retinopathy
how to culture salmonids
10-15degrees
5L/1000kg
incubate eggs at 4-12degrees
when do trout spawn
autumn-spring
when do salmon spawn
autumn-winter
sexual maturity of salmonids
males 2-4y
females 3-6y
how to get gonads from salmonids
stop feeding them 14d before stripping
sedate with MS222
in brown trout - remove ovarian fluid (not in rainbow)
what to do with eggs in salmonids
use male to female ratio 3:1
add water and mix
eggs will harden and macrophyte closes
disinfect eggs with organic iodine compounds within 10h of fertilisation or at eyed staged
remove dead/unfertilised eggs by soaking in 8% NaCl
incubate yolk sac larvae in baskets
what to do with fry in salmonids
keep indoors for 6-8w as light sensitive (2-4h of dark) - feed 12x/d (8% bw/d)
feed juveniles 6-8x/d then 2-4x/d with 40% pro
market size in 12-18m
how to grow out salmonids at sea
transfer juveniles in to sea cages
acclimatise slowly by gradually increasing salinity or feed them high salt
how long til salmonids hatch
at 10degrees:
rainbow trout - 31d
brown trout - 41d
atlantic salmon - 51d
Oomycetes
family = Saprolegniacene and Saprolegnia
fungal molds
signs = cotton wool like tufts
when = in low water temperatures
Ceratothoa oestroides
buccal parasite of marine fish
have a direct life cycle
Protistan ciliate parasites
cause = Trichodina, Apiosoma, Epistylis
some are commensals, some are true parasites
have a direct life cycle
infections due to poor water quality
Ichthyopthirius multifilis
protistan ciliate parasite
in fresh water fish
causes white spot disease
signs = increased mucus production, erosions
theronts are the free-swimming infective form
trophont are the feeding stage
treatment = Cu sulphate, salt, formalin if approved
prevention more important
treatment of protistan ciliate parasites
Cu sulphate, salt and formalin in approved
Trypanosoma and Trypanoplasma sp
hematozoic parasites
hosts = fresh water and marine fish
leeches are the intermediate host
signs = anemia, hemorrage, osmoregulatory problems due to kidney destruction
Monogean flatworms
Dactylogyrus, Gyrodactylus, Diplectanum
Gyrodactylus salaris = in salmon is OIE listed
hemaphrodites
oviparous except gyrodactylus who is viviparous
Diplostomum spathaceum
Digenea trematode
eye fluke
host = fresh water fish
signs = cataracts, exophthalmia, blindness, decreased growth due to decreased feeding
life cycle = indirect, snails are intermediate host
mostly hermaphrodites and oviparous
Apicomplexans
cause = Eimeria and Goussia sp
host = fresh and marine water fish
intracellular intestinal parasites with direct life cycle within host cell
entry = ingestion of oocysts
control = draining, drying, freezing, liming. anticoccidial drugs work but are not approved
who gets Eimeria dicentrarchi
Seabass
what does Goussa carpelli do
coccidian enteritis
what does Goussia supepithelialis do
nodular coccidiosis
lethargy, decreased appetite, abdominal distension, severe enteritis
myxozoa life cycle
myxospore goes in to annelid worms which release actinospores which are infective to fish
Myxozoa diseases
swim bladder inflammation
whirling disease
swim bladder inflammation
in carp in August
signs = lethargy, swollen abdomen, unable to maintain equilibrium , red and thickened swim bladder
cause = Sphatospora dykovae
whirling disease
in salmonids
infects cartilage before ossification occurs leading to deformities, darkening of caudal region and whirling
cause = Myxobolus cerebralis
cause of whirling disease
Myxobolus cerebralis
cause of swim bladder inflammation
Sphatospora dykovae
Cestodes
endoparasites in digestive tract (anterior part)
hermaphrodites
order = caryophyllidea, caryophyllaceus fimbriceps
signs = swollen abdomen, stop eating, hemorrhagic enteritis, emaciation
control = draining, drying and liming, anthelminthics, niclosamide effective but not registered
Bothriocephalosis
cause = Bothriocephalus acheilognathi (cestode - Asian tapeworm up to 8cm)
affects = carp and cyprinids
mortality = 100% in young fish
signs = decreased growth, swollen abdomen, emaciation, hemorrhagic enteritis, severe GI tract damage
types of muscle
cardiac
smooth
skeletal - head, trunk, tail and fins
axial muscle
organised in myomeres
myomeres separated by myosepta
red fibres
highly vascularised for long term swimming
white fibres
poorly vascularised, for bursts of energy in strong swimming
scales
placoid - sharks and rays
ganoid - sturgeons
cosmoid - ancient
elasmoid - teleosts
2 types of elasmoid - cycloid and ctenoid
cycloid - salmonids and cyprinids
ctenoid - perch and pikeperch
pigment cells
melanophores - black
erythrophores - red
zanthophores - yellow
iridophores - shiny
colour changes can be physiological or morphological
blood flow in the gills
a. brachialis - lamellar arteries - secondary lamella - lamellar arteries - a. epibranchialis
breathing
active in cyprinids
passive in salmonids - need to continuously swim
gills
4 pairs of gill arches supported by cartilage and ro bony skeleton
on each gill arch = outer surface has 2 rows of gill filaments (primary lamella) and inner surface has gill rakers
lamella
primary = supported by cartilage
secondary = gaseous exchange
opercular cavity
operculum (branchiostegal membrane)
OIE listed viral diseases
IHN
koi herpes virus
spring viremia of carp
VHS
spring viremia of carp
cause = Rhabdovirus carpio
affects = mostly common carp
transmission = horizontal through diseased fish
vectors = parasites
outbreaks = 11-17deg
mortality = 1-40%
signs = hemorrhagic anemia, edema, enteritis and peritonitis
cause of spring viremia of carp
Rhabdovirus carpio
carp pox
cause = cyprinid herpes virus 1
outbreaks = 15deg in winter and early spring
mortality = high in juveniles
signs = benign, hyperplastic, papillomatous growths in skin
cause of carp pox
cyprinid herpes virus 1
koi herpes virus
cause = cyprinid herpes virus 3
affects = common and koi carp
outbreaks = 16-25deg
morbidity = up to 100%
mortality = 70-80%
transmission = horizontal
vectors = birds, parasites, fish
signs = gill necrosis, enophthalmia
cause of koi herpes virus
cyprinid herpes virus 3
skin
epidermis - upper layer with mucous cells
dermis - lower layer
hypodermis
where are scales
in dermis
layers of dermis
stratum spongiosum - loose connective tissue with capillaries and pigment cells
stratum compactum - dense connective tissue
scales
fins
skin fold supported by bony rays
rays can be spiny or soft
paired fins
pectoral and pelvic
unpaired fins
dorsal, caudal and anal
who has adipose skin
Salmonids and Ictauridae
who doesn’t have pelvic fins
eels
heart
1 atrium and 1 ventricle
HR varies with water temp - around 30bpm
blood
contains hemocytes and plasma
pH 7.6
pyloric caeca
blind ending diverticula between stomach and anterior intestine
cyprinid GI tract
no stomach but have extended anterior intestine
swim bladder
hydrostatic organ that is filled/emptied to regulate buoyancy
tunica interna - transparent epithelial layer, overlying muscularis, mucosa and submucosa of loose connective tissue
tunica externa - fibrous layer with muscle and elastic connective tissue
gas inside = mostly N2
closed/open swim bladder
physoclists (closed)
physostomes
swim bladder closes 24-36h post hatching in carp
3w post hatching in trout
swim bladder in carp
2 chambers with diaphragm
which organs are responsible for osmoregulation
skin, gills, kidney and alimentary canal
freshwater fish osmoregulation
their environment is hypo osmotic
water passes in to the body so they dont have to drink
kidney produces lots of dilute urine
ions are passively lost through gills, skin and urine
ions are actively taken up from food and gills
marine fish osmoregulation
their environment is hyper osmotic
water is lost through skin and gills so they have to drink
produce small amounts of concentrated urine - low GFR
excess ions are excreted in gills, faeces and urine
arthropoda
cause = Argulus foliaceus, Lernaea cyprinacea
have a direct life cycle
ectoparasite - attach to gills (L.c) or skin (A.f) with 2 round suckers or anchors then feed on blood and tissue
cause of pasteurellosis
Photobacterium damsela spp piscicida
who gets pasteurellosis
marine fish
predisposing for pasteurellosis
seabass and bream susceptible when under 50g
18-20deg
lower temps = subclinical disease
entry of pasteurellosis and pathogenesis
through skin and intestine
per acute-acute = in fry, non specific external signs
subacute-chronic = older fish, nodular white granulomas in spleen, liver, kidney and skeletal muscle
diagnosis of pasteurellosis
isolate from kidney or spleen
treatment of pasteurellosis
oxytetracycline, florfenicol, flumequine
can fail due to resistance and the fact bacteria live in macrophages
prevention of pasteurellosis
vaccination
koi sleepy disease
cause = carp edema virus - DNA poxvirus
affects = common and koi carp
outbreaks = koi - 15-25deg, common - 6-10deg
all ages susceptible
signs = enopthalmia, lethargy and oedematous gills
viral hemorrhagic septicaemia
cause = Rhabdoviridae VHS virus
hosts = salmonids, trout, flat fish and pike
outbreak = less than 14deg, fluctuating temps
mortality = 100% in fry, 30-70% in older
transmission = horizontal, vectors - birds
types of VHS
acute = lethargy, erratic swimming, pale gills and liver, bleeding in skeletal muscle and adipose tissue, edema in spleen and kidneys, ascites
chronic = dark skin, exophthalmia, pale and grey liver, mortality prolonged but not high
nervous = abnormal swimming, low mortality
control of VHS
good hygiene
disinfection
select fish for genetic resistance
diagnosis of furunculosis
isolate from kidneys
treatment of furunculosis
oxytetracycline, florfenicol, potentiated sulphonamides in feed
control of furunculosis
good husbandry, disinfect fertilised eggs, vaccinate salmon
bacterial cold water disease
cause = Flavoacterium psychrophilum
host = salmonids
predisposing = less than 10deg, poor water quality
transmission = horizontal or vertical
entry = damaged skin and fins
2 types - rainbow trout fry syndrome and bacterial cold water disease
treatment = oxytetracycline, florfenicol, amoxicillin in feed
diagnosis = isolate from kidney or spleen on special media
rainbow trout fry syndrome
cause = Flavobacterium pschrophilum
signs = acute septicaemia
internal pathology predominates, fin erosion, exophthalmia, ascites
50% mortality
bacterial cold water disease sign
older fish
external pathology predominates
ulcers, yellow pigment, damaged fin tips
70% morbidity
cause of bacterial kidney disease
Renibacterium salmoninarium
who gets bacterial kidney disease
salmonids
predisposing for bacterial kidney disease
overstocking and carrier brood stock
signs of bacterial kidney disease
lesions in kidney, heart, spleen and liver
white caseous, nodular granulomas
cause of carp erythrodermatitis
Aeromonas salmonicida spp nova
hosts of carp erythrodermatitis
warm water fish - cyprinids, pike, catfish
2 courses of carp erythrodermatitis
summer - faster course and good prognosis
autumn - slower course and bad prognosis
entry for carp erythrodermatitis
through skin
Bacteria multiplies and causes inflammation between epidermis and dermis
leads to tissue necrosis and osmotic imbalance
signs of carp erythrodermatitis
ulcers - red centres and white periphery
exophthalmia, ascites, secondary infections
dark pigmented scars
diagnosis of carp erythrodermatitis
isolate from edge of ulcers, grow on blood media
treatment of carp erythrodermatitis
oxytetracycline, florfenicol, flumequine
control of carp erythrodermatitis
prevent birds, careful handling, breed resistant strains
cause of bacterial cold water disease
Flavobacterium psychrophilum
predisposing for cold water disease
low temps of less than 10
poor water quality
cause of enteric red mouth disease
Yersinia ruckeri
host of enteric red mouth
salmonids
predisposing for enteric red mouth
temp changes 8-16 deg
stress
fastest disease course at 18 deg
signs of enteric red mouth
haemorrhages in and around mouth and on fin bases
empty intestines with hemorrhage
swollen kidney and splenomegaly
control of enteric red mouth
disinfect eggs
vaccine and booster needed
who has hepatopancreas
cyprinids
cause of IHN
rhabdoviridae
who gets IHN
young trout and salmon
mortality of IHN
100% in fry and 30% in older fish
when do IHN outbreaks occur
10-12 deg
signs of IHN
lethargy, decreased appetite, abnormal swimming
sub dermal hemorrhage in fins
pale gills, liver, kidney and spleen
ascites and exophthalmia
fecal casts, yellow/white fluid in GI tract
control of IHN
good hygiene and disinfections
cause of IPN
Birnaviridae
who does IPN affect
young salmonids and eels
when do IPN outbreaks occur
10 deg
signs of IPN
abnormal swimming
skin darkening
abdo distension
hemorrhage on ventral surface and edema
catarrhal enteritis and fecal casts
prevention of IPN
vaccine for Atlantic salmon
cause of furunculosis
Aeromonas salmonicida spp salmonicida
predisposing for furunculosis
sudden increase in temp 12-15deg
stress
route of entry of furunculosis
skin, gills, gut and causes septicaemia
types of furunculosis
peracute - in juveniles, sudden death with no signs or dark skin and exophthalmia
acute - in growing fish, internal hemorrhage and on fin bases
subacute/chronic - older fish, hemorrhage and furuncles
diagnosis of furunculosis
isolate from kidneys
treatment of furunculosis
medicated feed - oxytetracycline, florfenicol, potentiated sulphonamides
control of furunculosis
good husbandry, disinfect fertilised eggs
vaccinate salmon
when do VHS outbreaks occur
less than 14 deg
fluctuating temps
hosts of VHS
salmonids, trout, flatfish, pike
cause of Tenabaculosis
Tenacibaculum maritum
hosts of tenabaculosis
Marine fish up to 100g
predisposing for tenabaculosis
stress
overstocking
sun burn - uv
signs of tenabaculosis
necrosis on gills
ulcers on skin
rot on fins
treatment of tenabaculosis
antimicrobials in feed
bath with hydrogen peroxide of formalin
what is tenabaculosis known as
marine columnaris
arthropoda species
Argulus foliaceus
Lernaea cyprinacea
signs of ectoparasite (arthropoda infections)
skin irritation
sudden movements
stop eating
hyperplasia of epithelium
increased mucus production
cloudy skin
Mycobacteriosis cause
Mycobacterium marinum
also known as Fish tuberculosis
fish handlers disease and swimming pool granuloma
cause of viral encephalopathy and retinopathy
Nodaviridae
who gets VER
sea bass an sea bream
when does VER occur
higher temps - 22deg
signs of VER
loss of appetite
abnormal swimming
dark pigmentation
swollen swim bladder
belly up at rest
vacuolation and necrosis of nervous cells of spinal cord, brain and or retina
intracytoplasmic inclusions
cestode name
caryophyllaceus fimbriceps
